1. Field of the Invention
The present invention is directed to a water pump of the type which includes a rotary shaft rotatably carried on a pump case and having a power transmitting rotary wheel at an axially outer end of the shaft, with the axially inner end of the rotary shaft projecting into a pump chamber defined in the pump case, and a mechanical seal interposed between the rotary shaft and the pump case to face the pump chamber.
2. Description of the Prior Art
Such a water pump is conventionally known, for example, from Japanese Laid-Open Utility Model Application No. 169230/86, wherein the mechanical seal is interposed at a location inward of the bearings in an axial direction of the rotary shaft between the pump case and the rotary shaft carried on the pump case with bearings interposed therebetween. In order to prevent water leakage through the mechanical seal from penetrating into the bearings, a baffle plate is provided on the rotary shaft between the bearings and the mechanical seal, and the pump case is provided with a discharge hole for discharging the water.
In the prior art water pump, however, it is difficult to completely discharge the water from the discharge hole by the aid of the baffle plate which rotates together with the rotary shaft, and it is difficult to reliably inhibit the penetration of water vapor into the bearings.